Mono-and dicresyl phosphate amine rust inhibitors

ABSTRACT

A RUST INHIBITOR SYNTHESIZED BY REACTING CRESYLIC ACID WTH PHOSPHORUS PENTOXIDE TO FORM MONO- AND DI-ARYL ACID PHOSPHATES WHICH ARE THEN NEUTRALIZED WITH AN IMIDAZOLINE, AND A PROCESS FOR PRODUCING SUCH RUSH INHIBITOR IN DESCRIBED. THE RUST INHIBITOR IS USEFUL IN GASOLINES, INCLUDING GASOLINES CONTAINING T-BUTYL ALCOHOL.

United States Patent Office 3,736,110 Patented May 29, 1973 3,736,110 MONO- AND DICRESYL PHOSPHATE AMINE RUST INHIBITORS Ernest H. Owston, Jr., Corona, and Robert L. Dinsmore, Long Beach, Calif., assignors to Atlantic Richfield Company, Philadelphia, Pa. N Drawing. Filed June 24, 1969, Ser. No. 836,170 Int. Cl. C101 1/26 US. CI. 44-56 3 Claims ABSTRACT OF THE DISCLOSURE A rust inhibitor synthesized by reacting cresylic acid with phosphorus pentoxide to form monoand di-aryl acid phosphates which are then neutralized with an imidazoline, and a process for producing such rust inhibitors is described. The rust inhibitor is useful in gasolines, including gasolines containing t-butyl alcohol.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to rust inhibitors and, more particularly, to organic imidazoline salts of monoand dicresylic phosphates.

Description of the prior art Rust inhibitors formed from the reaction of alkyl alcohols with P 0 and neutralization of the phosphate with an amine are known. However, to our knowledge, aryl phosphate amines have not been heretofore known to possess rust inhibiting properties. Compounds of this general class and the particular compounds described hereinafter have now been found to possess unexpectedly advantageous rust inhibiting characteristics. Accordingly, it is the object of this invention to provide an improved rust inhibiting composition and a process for producing the same.

SUMMARY OF THE INVENTION This invention comprises a rust inhibiting composition which is best described in terms of its method of preparation. The composition comprises the reaction product of petroleum cresylic acids with phosphorus pentoxide neutralized by reaction with an organic imidazoline. It is, therefore, the object of this invention to provide a process for producing a rust inhibitor and the product of the process as a rust inhibitor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The inventive process comprises, first, reacting petroleum cresylic acids with P 0 to form a mixture of monoand di-aryl acid phosphates and, secondly, neutralizing this product with an imidazoline to form the rust inhibiting composition of the invention.

The term cresylic acid in this application is used in the sense that it is used in the petroleum trade; i.e., the designation for commercial mixtures of phenolic materials boiling in the cresylic acid range. Cresylic acid consists of phenols, cresols, and xylenols in various proportions. Cresylic acid may be derived from petroleum or from coal tar. Petroleum derived cresylic acid is preferred for this invention, however. A typical cresylic acid composition,

useful in this invention, contains about 10 percent phenol, 30 percent cresols, 40 percent xylenols, and about 3 percent higher phenols. This is not, however, a critical ratio and the cresylic acid useful in this invention may be defined simply as containing a major portion of cresols and xylenols with minor proportions of higher and lower molecular weight phenolic compounds.

The cresylic acid is dry distilled and reacted, preferably, in a solvent such as toluene, with P 0 The reaction may be carried out at room temperatures, and temperature does not appear to be a critical variable. P 0 in a proportion to provide a mixture of monoand di-aryl acid phosphates is used. The amount of P 0 therefore, is calculated according to the composition of the particular cresylic acid used in the process.

The acid phosphate, which is insoluble in the toluene solvent, is then neutralized with an organic imidazoline. Amines of this type having molecular weights from about 270 to about 400 are preferred. Typical of such amines is a commercially available amine described as Geigy amine O, which is an imidazoline of molecular weight 355 having the following formula:

in which n is at least about 10 and wherein R is a C to C averaging about C alkyl, aryl, or aralkyl group.

In a specific embodiment, A mole (28.6 gms.) of cresylic acid containing about 10 percent phenol, 30 p'ercent cresols, 40 percent xylenols, and 3 percent higher phenols, was dissolved in 500 millilitres of toluene and reacted, by stirring at room temperature, with /2 mole P 0 to give a reaction mixture comprising monoand di-aryl phosphates. The cresylic acid was derived from California base petroleum and was dry distilled. The monoand di-aryl phosphate was neutralized with 4 mole +5 excess) Geigy Amine 0 described previously.

The rust inhibiting effect of the product of the above process was tested in reagent toluene. ASTM 1020 cold rolled steel strips prepolished with a 100 grit Carborundum belt sander and rinsed in acetone were the test samples. The metal strips, after preparation, were placed in test bottles and allowed to soak for approximately 16 hours completely immersed. At the end of 16 hours, 10 mls. of HBr acidified deionized water at pH 3 was added to mls. of test hydrocarbon, the starting volume, and shaken for 15 seconds. The 8 oz. square bottles in which the tests were run were capped with aluminum foil lined lids and laid horizontally such that the strip was immersed in the test fuel and water, crossing the water interface. The strips were rated, shaken 15 seconds, and returned to the horizontal position at the desired intervals, beginning after 30 minutes. A control, which contained no additives, was compared with toluene and the test feed containing the inventive additive in the ratio of 6 pounds per thousand barrels were compared. Some 50 commercial additives were compared using the same procedure. The additive of this invention, cresylic Amine 0 phosphate, was comparable with the 5 best additives, at a ratio of 6 pounds per thousand barrels. The results of these tests are given in Table I,

TAB LE I [Evaluations of corrosion inhibitor additives-static rust test method- 10% H3r acidified deionized water in 90% Baker analyzed toluene reagent Estimation oi percent of TABLE III [Evaluation of corrosion inhibitorstatic rust test method-10% HBr acidified deionized water in premium base gasoline to determine ARCONOL efiect] Estimation of percent rusted area on 1,1020 of rusted area on cold rolled steel spec- 1,020 cold rolled steel imcn after 72 hrs. fuclspecimen after 48 hrs. Total water contact incl-water contact cone,

lb Fuel Water Fuel Water Additive identification Mbbl. phase phase Additiveidentification phase phase No inhibitor 0 60.8 87.0 No hibitor.. 25-30 50-60 Amyl phosphate-Armour Duomene 'T, Cresylic Amine O phosophate at 6 lbs./Mbbl 5-6 5-10 reacted 6 20-25 5-6 N0 h it L. 3; 26-30 66-70 Amyl phosphate-Armour Duomene T, Cresylic Amine 0 phosphate 2 at 6 lbsJMbbL. 5-6 20-25 Amine O at 31bs./Mbbl 9 Trace-1.0 2-3 1 h g oline base is without inhibitor additives but includes meta CresylicA.mineO"phospha-te 6 2-3 2-3 deactivator antioxidant and leaded. Naphthenic Acid plus 2 Contains ARCONOL (oxirane tertiary butyl alcohol) with 2.0%

Amine C 6 70-75 50-60 Water content In the fuel at 10. 0 volume percent.

Amine 6 in: tax

A 8-. i 6 1f 6 A TM Rust Test D-665-60, modified to run 16 hours, Atlantic ARI-1 at 8 l s-l P1113 rather than the usual 4 ho r wa Geigy Amine 0 at 31bs./Mbbl a Trace 3-1 fir f h S run to conlpare i Geigy sarkosyllt I VMBHI T 6 Ho 20 e ect 0 t e inventive additive under dynamic condi- Geigy Sarkosyl at 3 bs. pus tions, A i

Geigy Amine Omalbs'lMbbl 6 Trace k3 s he data in Table IV show, the inventiveaddi ceigysmkosyllo fb fiviggl y 5 Trace two is highly effective and is comparable or superior to Geigy Sarkosy O at 3 s. pus I Geigy Amine 0 at3lbs./Mbbl a Trace 1-3 thc best commerclal addtves Geggy saikosyl 8 at14b5lLbsh%liJliL plus 6 9 3 3 5 eigy mine at s. T L I Geigy SarkosylS 6 Trace 5-19 AB E Geigy Sarkosyl S at 3 lbsJMbbl. plus [Evaluations of corrosion inhibitor addit vesAsTM D-665-60 rust test Geigy AmineO at8lbs./Mbbl 6 Trace 3-5 method regular grade base gasoline 2 in the presence of deionized Lubrizol 541 6 Trace 5-10 water] Lubrizol 850 6 3-4 5-6 Tetrolite Tolad244 6 Trace 20-25 Cogc R t S 115 1 Average. Additive identification Mbbl ratings 3 No inhibitor o E Cresylic Amine 0" phosphate 6 A AtlanticARl-l 6 A A second test was made using unleaded premium base ;g= g, 1;, 6 A gasoline, without corrosion inhibitor. Out of 13 of the gigg'usygrmiiglliatfilbs./Mbbl. plus Geigy Amine 0 6 l 4 V best additives previously tested, us ng the same procedure Geigy sarkosyl O at 31bs /Mbb1 plus Geigy Amine O as before except substituting gasoline in place of toluene, g gl lgsg bbl g, I the additive of this invention was rated as one of the best o h f a d wat bas s, This test modified to run 16 hours at room tem erature (a roxithree for rust glotecnon l b T II p 40 mately 77 0 If.) and is a dynamic rust test. p pp The results of t is test are given in a e Tlie gasoline base is Without inhibitonadditives but includes 5.0

volume percent tertiary butyl alcohol (with impurities including water), mcrtillsttlelaactt vator aitlil antioxidant and leaded.

lugs 85 O OVSZ A-no visible rust. TABLE II B+ 5.0% rust.

B525% rust. [Evaluations of corrosion inhibitor additivesstatic rust E75-100% rust.

test method-10% HBr acidified deionized water in 90% unleaded premium base gasoline E I f f t As will be apparent from the foregoing, the compos i f l ggg ggfi tions of this invention may be developed using cresylic 1,02 ooldrolled acid phosphates neutralized with a large variety of imidazgg f ff fgfgg z ohms. Variations and substitutions of imidazolines and Total contact other amines and variations in the process may be made, fags; Fuel Water within reasonable limits, without departing from the spirit Additive identification Mbbl. Phase Phas and scope of the invention, as defined in the claims which No inhibitor 0 15-20 75-85 follow- Cresylic Amine 0'' phosphate 6 Trace-1.0 3-5 We cla m; Atlantic ARI-1 e 8-10 a 0, 21% 21%? plus 6 T Hi 1. Rust inhibiting compositions prepared by a process eigy mine at s. race Geigy sarkosylL 6 Trace H comprlsmg the Steps o firs reacting crcsylic acid with cg SgrkosylQL ag lbsJgldabbl. plus 6 T T 1 O phosphorus pentoxidc in an amount to form a mixture of (i1 mine 8 S. race race- Geigyggmkosyl 0 ff 6 H H n y ph spha s and, secondly, at leastneu- Gt sixkqsyloO fits fblbfiwlgiibl. plus 6 0 3 5 tralizlng said monoand di-aryl phosphates with an imideigy mine a s. Geigy sarkosyl S at 3 lbsJMbbL plus azoline having a molecular weight of between 150 and Lclibeigylignlilne o at3lbs./Mbbl e Trace-1.0 2-4 400 and containin at least one C to C alkyl group. 3 ,223, 1 2' 5;; The P t f Claim 1 wherein the imidazoline Tretolite Tolad 244 a 8-10 25-30 is of the following formula:

1 The gasoline base is without inhibitor additives but includes metal dcactivator and antiozidant.

N CH, (/HaU/HzhC N-CH2 A static rust test was run using a fuel containing ARCONOL (Oxirane tertiary butyl alcohol). Comparatwo results are given in Table III. Itwill be noted that, wherein n is from 10 to 30 and R is a C to C alkyl, quite unexpectedly, the corrosion inhibitor of this invenaryl or aralkyl group. t on is highly effective even in the more corrosive gaso- 3. A motor fuel comprising gasoline containing tertiary lino-tern y butyl alcohol oo po i i i butyl alcoho and he reactio p o uct t o y io acid,

phosphorus pentoxide and an imidazoline of the following formula:

References Cited UNITED STATES PATENTS Vaughn 252- 389 Vaughn 252389 Vaughn 252389 Cantrell et al. 252-389 Vaughn 252389 Leland et al, 252-389 Cantrell et al. 252389 LeSuer 25238'9 OTHER REFERENCES Geigy Industrial Chemicals, page 12.

DANIEL E. WYMAN, Primary Examiner Schaak, Jr. 15 Y. H. SMITH, Assistant Examiner Benning et al. 4469 P Andress, Jr 4469 P Turner 252389 44DIG. 63; 252389 

